Growing Annual Flowers from Seed

Annuals can be started indoors from seeds, sown directly in the garden, or purchased as 'bedding plants' from your local gardening center. If you start plants from seeds indoors, the seeds are usually sown eight to ten weeks before the last spring frost. If you raise your own transplants, be sure to harden them off by exposing them to outside conditions before planting in their intended site.

Before planting your seeds it is necessary to prepare your soil. Work your soil about 6 to 8 inches (15 to 20 cm) deep and be sure to mix in some organic matter such as well-rotted manure or compost, then rake it smooth.

Annuals seeded in the garden sometimes fail to germinate properly because the soil surface crusts and prevents entry of water. One way to overcome this is to make a furrow in the soil about 1/2-inch (12 mm) deep and fill with vermiculite (if the soil is dry, water the furrow before filling with vermiculite).

Then make a shallow furrow in the vermiculite and sow the seed at the rate recommended on the package. Cover the seeds with vermiculite and use a nozzle adjusted to a fine mist to water the seeded area thoroughly.

Cover seed very lightly. Some gardeners like to sift fine soil through a box or pan with a fine wire mesh on the bottom. After covering the seed, tamp the soil. An easy way to do this is to use a flat board that you step on to improve contact between seed and soil.

Keep the seed bed well watered or cover with a mulch such as newspaper to prevent excessive evaporation and soil drying. Remove the mulch promptly after germination begins so young seedlings will receive adequate sunlight.

When most outdoor-seeded annuals develop their first pair of true leaves, they should be thinned to the recommended spacing. Excess seedlings can often be transplanted to another spot. This is especially true for seedlings growing in vermiculite-filled furrows.

Zinnias are an exception to this rule of thinning. In many cultivars of zinnias, some flowers may appear with a large, nearly naked corolla and few colorful petals. This phenomenon is sometimes referred to as "Mexican hats".

To eliminate such plants, sow two or three seeds at each location, wait until the plants start lowering, and then remove plants with this undesirable characteristic. Thin the remaining plants to the recommended 8- to 12-inch spacing.

Another exception is sweet alyssum, which is particularly susceptible to damping-off fungal disease. To insure a good stand of alyssum, sow seeds in hills.

When planting your annuals be sure to use a quality root stimulator at the time of planting and for the first 4 - 6 waterings to follow. This will get your plants off to quick start by promoting vigorous root growth.